//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  Preparation of data for rendering,
//  generation of lookups, caching, retrieval by name.
//

#include <stdio.h>

#include "deh_main.h"
#include "i_swap.h"
#include "i_system.h"
#include "z_zone.h"


#include "w_wad.h"

#include "doomdef.h"
#include "m_misc.h"
#include "r_local.h"
#include "p_local.h"

#include "doomstat.h"
#include "r_sky.h"


#include "r_data.h"

//
// Graphics.
// DOOM graphics for walls and sprites
// is stored in vertical runs of opaque pixels (posts).
// A column is composed of zero or more posts,
// a patch or sprite is composed of zero or more columns.
//



//
// Texture definition.
// Each texture is composed of one or more patches,
// with patches being lumps stored in the WAD.
// The lumps are referenced by number, and patched
// into the rectangular texture space using origin
// and possibly other attributes.
//
typedef struct
{
    short   originx;
    short   originy;
    short   patch;
    short   stepdir;
    short   colormap;
} PACKEDATTR mappatch_t;


//
// Texture definition.
// A DOOM wall texture is a list of patches
// which are to be combined in a predefined order.
//
typedef struct
{
    char        name[8];
    int         masked;
    short       width;
    short       height;
    int                 obsolete;
    short       patchcount;
    mappatch_t  patches[1];
} PACKEDATTR maptexture_t;


// A single patch from a texture definition,
//  basically a rectangular area within
//  the texture rectangle.
typedef struct
{
    // Block origin (allways UL),
    // which has allready accounted
    // for the internal origin of the patch.
    short   originx;
    short   originy;
    int     patch;
} texpatch_t;


// A maptexturedef_t describes a rectangular texture,
//  which is composed of one or more mappatch_t structures
//  that arrange graphic patches.

typedef struct texture_s texture_t;

struct texture_s
{
    // Keep name for switch changing, etc.
    char    name[8];
    short   width;
    short   height;

    // Index in textures list

    int         index;

    // Next in hash table chain

    texture_t  *next;

    // All the patches[patchcount]
    //  are drawn back to front into the cached texture.
    short   patchcount;
    texpatch_t  patches[1];
};



int     firstflat;
int     lastflat;
int     numflats;

int     firstpatch;
int     lastpatch;
int     numpatches;

int     firstspritelump;
int     lastspritelump;
int     numspritelumps;

int     numtextures;
texture_t** textures;
texture_t**     textures_hashtable;


int*            texturewidthmask;
// needed for texture pegging
fixed_t*        textureheight;
int*            texturecompositesize;
short**         texturecolumnlump;
unsigned short**    texturecolumnofs;
byte**          texturecomposite;

// for global animation
int*        flattranslation;
int*        texturetranslation;

// needed for pre rendering
fixed_t*    spritewidth;
fixed_t*    spriteoffset;
fixed_t*    spritetopoffset;

lighttable_t    *colormaps;


//
// MAPTEXTURE_T CACHING
// When a texture is first needed,
//  it counts the number of composite columns
//  required in the texture and allocates space
//  for a column directory and any new columns.
// The directory will simply point inside other patches
//  if there is only one patch in a given column,
//  but any columns with multiple patches
//  will have new column_ts generated.
//



//
// R_DrawColumnInCache
// Clip and draw a column
//  from a patch into a cached post.
//
void
R_DrawColumnInCache
( column_t* patch,
  byte*     cache,
  int       originy,
  int       cacheheight )
{
    int     count;
    int     position;
    byte*   source;

    while (patch->topdelta != 0xff)
    {
    source = (byte *)patch + 3;
    count = patch->length;
    position = originy + patch->topdelta;

    if (position < 0)
    {
        count += position;
        position = 0;
    }

    if (position + count > cacheheight)
        count = cacheheight - position;

    if (count > 0)
        memcpy (cache + position, source, count);

    patch = (column_t *)(  (byte *)patch + patch->length + 4);
    }
}



//
// R_GenerateComposite
// Using the texture definition,
//  the composite texture is created from the patches,
//  and each column is cached.
//
void R_GenerateComposite (int texnum)
{
    byte*       block;
    texture_t*      texture;
    texpatch_t*     patch;
    patch_t*        realpatch;
    int         x;
    int         x1;
    int         x2;
    int         i;
    column_t*       patchcol;
    short*      collump;
    unsigned short* colofs;

    texture = textures[texnum];

    block = Z_Malloc (texturecompositesize[texnum],
              PU_STATIC,
              &texturecomposite[texnum]);

    collump = texturecolumnlump[texnum];
    colofs = texturecolumnofs[texnum];

    // Composite the columns together.
    patch = texture->patches;

    for (i=0 , patch = texture->patches;
     i<texture->patchcount;
     i++, patch++)
    {
    realpatch = W_CacheLumpNum (patch->patch, PU_CACHE);
    x1 = patch->originx;
    x2 = x1 + SHORT(realpatch->width);

    if (x1<0)
        x = 0;
    else
        x = x1;

    if (x2 > texture->width)
        x2 = texture->width;

    for ( ; x<x2 ; x++)
    {
        // Column does not have multiple patches?
        if (collump[x] >= 0)
        continue;

        patchcol = (column_t *)((byte *)realpatch
                    + LONG(realpatch->columnofs[x-x1]));
        R_DrawColumnInCache (patchcol,
                 block + colofs[x],
                 patch->originy,
                 texture->height);
    }

    }

    // Now that the texture has been built in column cache,
    //  it is purgable from zone memory.
    Z_ChangeTag (block, PU_CACHE);
}



//
// R_GenerateLookup
//
void R_GenerateLookup (int texnum)
{
    texture_t*      texture;
    byte*       patchcount; // patchcount[texture->width]
    texpatch_t*     patch;
    patch_t*        realpatch;
    int         x;
    int         x1;
    int         x2;
    int         i;
    short*      collump;
    unsigned short* colofs;

    texture = textures[texnum];

    // Composited texture not created yet.
    texturecomposite[texnum] = 0;

    texturecompositesize[texnum] = 0;
    collump = texturecolumnlump[texnum];
    colofs = texturecolumnofs[texnum];

    // Now count the number of columns
    //  that are covered by more than one patch.
    // Fill in the lump / offset, so columns
    //  with only a single patch are all done.
    patchcount = (byte *) Z_Malloc(texture->width, PU_STATIC, &patchcount);
    memset (patchcount, 0, texture->width);
    patch = texture->patches;

    for (i=0 , patch = texture->patches;
     i<texture->patchcount;
     i++, patch++)
    {
    realpatch = W_CacheLumpNum (patch->patch, PU_CACHE);
    x1 = patch->originx;
    x2 = x1 + SHORT(realpatch->width);

    if (x1 < 0)
        x = 0;
    else
        x = x1;

    if (x2 > texture->width)
        x2 = texture->width;
    for ( ; x<x2 ; x++)
    {
        patchcount[x]++;
        collump[x] = patch->patch;
        colofs[x] = LONG(realpatch->columnofs[x-x1])+3;
    }
    }

    for (x=0 ; x<texture->width ; x++)
    {
    if (!patchcount[x])
    {
        printf ("R_GenerateLookup: column without a patch (%s)\n",
            texture->name);
        return;
    }
    // I_Error ("R_GenerateLookup: column without a patch");

    if (patchcount[x] > 1)
    {
        // Use the cached block.
        collump[x] = -1;
        colofs[x] = texturecompositesize[texnum];

        if (texturecompositesize[texnum] > 0x10000-texture->height)
        {
        I_Error ("R_GenerateLookup: texture %i is >64k",
             texnum);
        }

        texturecompositesize[texnum] += texture->height;
    }
    }

    Z_Free(patchcount);
}




//
// R_GetColumn
//
byte*
R_GetColumn
( int       tex,
  int       col )
{
    int     lump;
    int     ofs;

    col &= texturewidthmask[tex];
    lump = texturecolumnlump[tex][col];
    ofs = texturecolumnofs[tex][col];

    if (lump > 0)
    return (byte *)W_CacheLumpNum(lump,PU_CACHE)+ofs;

    if (!texturecomposite[tex])
    R_GenerateComposite (tex);

    return texturecomposite[tex] + ofs;
}


static void GenerateTextureHashTable(void)
{
    texture_t **rover;
    int i;
    int key;

    textures_hashtable
            = Z_Malloc(sizeof(texture_t *) * numtextures, PU_STATIC, 0);

    memset(textures_hashtable, 0, sizeof(texture_t *) * numtextures);

    // Add all textures to hash table

    for (i=0; i<numtextures; ++i)
    {
        // Store index

        textures[i]->index = i;

        // Vanilla Doom does a linear search of the texures array
        // and stops at the first entry it finds.  If there are two
        // entries with the same name, the first one in the array
        // wins. The new entry must therefore be added at the end
        // of the hash chain, so that earlier entries win.

        key = W_LumpNameHash(textures[i]->name) % numtextures;

        rover = &textures_hashtable[key];

        while (*rover != NULL)
        {
            rover = &(*rover)->next;
        }

        // Hook into hash table

        textures[i]->next = NULL;
        *rover = textures[i];
    }
}


//
// R_InitTextures
// Initializes the texture list
//  with the textures from the world map.
//
void R_InitTextures (void)
{
    maptexture_t*   mtexture;
    texture_t*      texture;
    mappatch_t*     mpatch;
    texpatch_t*     patch;

    int         i;
    int         j;

    int*        maptex;
    int*        maptex2;
    int*        maptex1;

    char        name[9];
    char*       names;
    char*       name_p;

    int*        patchlookup;

    int         totalwidth;
    int         nummappatches;
    int         offset;
    int         maxoff;
    int         maxoff2;
    int         numtextures1;
    int         numtextures2;

    int*        directory;

    int         temp1;
    int         temp2;
    int         temp3;


    // Load the patch names from pnames.lmp.
    name[8] = 0;
    names = W_CacheLumpName (DEH_String("PNAMES"), PU_STATIC);
    nummappatches = LONG ( *((int *)names) );
    name_p = names + 4;
    patchlookup = Z_Malloc(nummappatches*sizeof(*patchlookup), PU_STATIC, NULL);

    for (i = 0; i < nummappatches; i++)
    {
        M_StringCopy(name, name_p + i * 8, sizeof(name));
        patchlookup[i] = W_CheckNumForName(name);
    }
    W_ReleaseLumpName(DEH_String("PNAMES"));

    // Load the map texture definitions from textures.lmp.
    // The data is contained in one or two lumps,
    //  TEXTURE1 for shareware, plus TEXTURE2 for commercial.
    maptex = maptex1 = W_CacheLumpName (DEH_String("TEXTURE1"), PU_STATIC);
    numtextures1 = LONG(*maptex);
    maxoff = W_LumpLength (W_GetNumForName (DEH_String("TEXTURE1")));
    directory = maptex+1;

    if (W_CheckNumForName (DEH_String("TEXTURE2")) != -1)
    {
    maptex2 = W_CacheLumpName (DEH_String("TEXTURE2"), PU_STATIC);
    numtextures2 = LONG(*maptex2);
    maxoff2 = W_LumpLength (W_GetNumForName (DEH_String("TEXTURE2")));
    }
    else
    {
    maptex2 = NULL;
    numtextures2 = 0;
    maxoff2 = 0;
    }
    numtextures = numtextures1 + numtextures2;

    textures = Z_Malloc (numtextures * sizeof(*textures), PU_STATIC, 0);
    texturecolumnlump = Z_Malloc (numtextures * sizeof(*texturecolumnlump), PU_STATIC, 0);
    texturecolumnofs = Z_Malloc (numtextures * sizeof(*texturecolumnofs), PU_STATIC, 0);
    texturecomposite = Z_Malloc (numtextures * sizeof(*texturecomposite), PU_STATIC, 0);
    texturecompositesize = Z_Malloc (numtextures * sizeof(*texturecompositesize), PU_STATIC, 0);
    texturewidthmask = Z_Malloc (numtextures * sizeof(*texturewidthmask), PU_STATIC, 0);
    textureheight = Z_Malloc (numtextures * sizeof(*textureheight), PU_STATIC, 0);

    totalwidth = 0;

    //  Really complex printing shit...
    temp1 = W_GetNumForName (DEH_String("S_START"));  // P_???????
    temp2 = W_GetNumForName (DEH_String("S_END")) - 1;
    temp3 = ((temp2-temp1+63)/64) + ((numtextures+63)/64);

    // If stdout is a real console, use the classic vanilla "filling
    // up the box" effect, which uses backspace to "step back" inside
    // the box.  If stdout is a file, don't draw the box.

    if (I_ConsoleStdout())
    {
        printf("[");
        for (i = 0; i < temp3 + 9; i++)
            printf(" ");
        printf("]");
        for (i = 0; i < temp3 + 10; i++)
            printf("\b");
    }

    for (i=0 ; i<numtextures ; i++, directory++)
    {
    if (!(i&63))
        printf (".");

    if (i == numtextures1)
    {
        // Start looking in second texture file.
        maptex = maptex2;
        maxoff = maxoff2;
        directory = maptex+1;
    }

    offset = LONG(*directory);

    if (offset > maxoff)
        I_Error ("R_InitTextures: bad texture directory");

    mtexture = (maptexture_t *) ( (byte *)maptex + offset);

    texture = textures[i] =
        Z_Malloc (sizeof(texture_t)
              + sizeof(texpatch_t)*(SHORT(mtexture->patchcount)-1),
              PU_STATIC, 0);

    texture->width = SHORT(mtexture->width);
    texture->height = SHORT(mtexture->height);
    texture->patchcount = SHORT(mtexture->patchcount);

    memcpy (texture->name, mtexture->name, sizeof(texture->name));
    mpatch = &mtexture->patches[0];
    patch = &texture->patches[0];

    for (j=0 ; j<texture->patchcount ; j++, mpatch++, patch++)
    {
        patch->originx = SHORT(mpatch->originx);
        patch->originy = SHORT(mpatch->originy);
        patch->patch = patchlookup[SHORT(mpatch->patch)];
        if (patch->patch == -1)
        {
        I_Error ("R_InitTextures: Missing patch in texture %s",
             texture->name);
        }
    }
    texturecolumnlump[i] = Z_Malloc (texture->width*sizeof(**texturecolumnlump), PU_STATIC,0);
    texturecolumnofs[i] = Z_Malloc (texture->width*sizeof(**texturecolumnofs), PU_STATIC,0);

    j = 1;
    while (j*2 <= texture->width)
        j<<=1;

    texturewidthmask[i] = j-1;
    textureheight[i] = texture->height<<FRACBITS;

    totalwidth += texture->width;
    }

    Z_Free(patchlookup);

    W_ReleaseLumpName(DEH_String("TEXTURE1"));
    if (maptex2)
        W_ReleaseLumpName(DEH_String("TEXTURE2"));

    // Precalculate whatever possible.

    for (i=0 ; i<numtextures ; i++)
    R_GenerateLookup (i);

    // Create translation table for global animation.
    texturetranslation = Z_Malloc ((numtextures+1)*sizeof(*texturetranslation), PU_STATIC, 0);

    for (i=0 ; i<numtextures ; i++)
    texturetranslation[i] = i;

    GenerateTextureHashTable();
}



//
// R_InitFlats
//
void R_InitFlats (void)
{
    int     i;

    firstflat = W_GetNumForName (DEH_String("F_START")) + 1;
    lastflat = W_GetNumForName (DEH_String("F_END")) - 1;
    numflats = lastflat - firstflat + 1;

    // Create translation table for global animation.
    flattranslation = Z_Malloc ((numflats+1)*sizeof(*flattranslation), PU_STATIC, 0);

    for (i=0 ; i<numflats ; i++)
    flattranslation[i] = i;
}


//
// R_InitSpriteLumps
// Finds the width and hoffset of all sprites in the wad,
//  so the sprite does not need to be cached completely
//  just for having the header info ready during rendering.
//
void R_InitSpriteLumps (void)
{
    int     i;
    patch_t *patch;

    firstspritelump = W_GetNumForName (DEH_String("S_START")) + 1;
    lastspritelump = W_GetNumForName (DEH_String("S_END")) - 1;

    numspritelumps = lastspritelump - firstspritelump + 1;
    spritewidth = Z_Malloc (numspritelumps*sizeof(*spritewidth), PU_STATIC, 0);
    spriteoffset = Z_Malloc (numspritelumps*sizeof(*spriteoffset), PU_STATIC, 0);
    spritetopoffset = Z_Malloc (numspritelumps*sizeof(*spritetopoffset), PU_STATIC, 0);

    for (i=0 ; i< numspritelumps ; i++)
    {
    if (!(i&63))
        printf (".");

    patch = W_CacheLumpNum (firstspritelump+i, PU_CACHE);
    spritewidth[i] = SHORT(patch->width)<<FRACBITS;
    spriteoffset[i] = SHORT(patch->leftoffset)<<FRACBITS;
    spritetopoffset[i] = SHORT(patch->topoffset)<<FRACBITS;
    }
}



//
// R_InitColormaps
//
void R_InitColormaps (void)
{
    int lump;

    // Load in the light tables,
    //  256 byte align tables.
    lump = W_GetNumForName(DEH_String("COLORMAP"));
    colormaps = W_CacheLumpNum(lump, PU_STATIC);
}



//
// R_InitData
// Locates all the lumps
//  that will be used by all views
// Must be called after W_Init.
//
void R_InitData (void)
{
    R_InitTextures ();
    printf (".");
    R_InitFlats ();
    printf (".");
    R_InitSpriteLumps ();
    printf (".");
    R_InitColormaps ();
}



//
// R_FlatNumForName
// Retrieval, get a flat number for a flat name.
//
int R_FlatNumForName (char* name)
{
    int     i;
    char    namet[9];

    i = W_CheckNumForName (name);

    if (i == -1)
    {
    namet[8] = 0;
    memcpy (namet, name,8);
    I_Error ("R_FlatNumForName: %s not found",namet);
    }
    return i - firstflat;
}




//
// R_CheckTextureNumForName
// Check whether texture is available.
// Filter out NoTexture indicator.
//
int R_CheckTextureNumForName (char *name)
{
    texture_t *texture;
    int key;

    // "NoTexture" marker.
    if (name[0] == '-')
    return 0;

    key = W_LumpNameHash(name) % numtextures;

    texture=textures_hashtable[key];

    while (texture != NULL)
    {
    if (!strncasecmp (texture->name, name, 8) )
        return texture->index;

        texture = texture->next;
    }

    return -1;
}



//
// R_TextureNumForName
// Calls R_CheckTextureNumForName,
//  aborts with error message.
//
int R_TextureNumForName (char* name)
{
    int     i;

    i = R_CheckTextureNumForName (name);

    if (i==-1)
    {
    I_Error ("R_TextureNumForName: %s not found",
         name);
    }
    return i;
}




//
// R_PrecacheLevel
// Preloads all relevant graphics for the level.
//
int     flatmemory;
int     texturememory;
int     spritememory;

void R_PrecacheLevel (void)
{
    char*       flatpresent;
    char*       texturepresent;
    char*       spritepresent;

    int         i;
    int         j;
    int         k;
    int         lump;

    texture_t*      texture;
    thinker_t*      th;
    spriteframe_t*  sf;

    if (demoplayback)
    return;

    // Precache flats.
    flatpresent = Z_Malloc(numflats, PU_STATIC, NULL);
    memset (flatpresent,0,numflats);

    for (i=0 ; i<numsectors ; i++)
    {
    flatpresent[sectors[i].floorpic] = 1;
    flatpresent[sectors[i].ceilingpic] = 1;
    }

    flatmemory = 0;

    for (i=0 ; i<numflats ; i++)
    {
    if (flatpresent[i])
    {
        lump = firstflat + i;
        flatmemory += lumpinfo[lump].size;
        W_CacheLumpNum(lump, PU_CACHE);
    }
    }

    Z_Free(flatpresent);

    // Precache textures.
    texturepresent = Z_Malloc(numtextures, PU_STATIC, NULL);
    memset (texturepresent,0, numtextures);

    for (i=0 ; i<numsides ; i++)
    {
    texturepresent[sides[i].toptexture] = 1;
    texturepresent[sides[i].midtexture] = 1;
    texturepresent[sides[i].bottomtexture] = 1;
    }

    // Sky texture is always present.
    // Note that F_SKY1 is the name used to
    //  indicate a sky floor/ceiling as a flat,
    //  while the sky texture is stored like
    //  a wall texture, with an episode dependend
    //  name.
    texturepresent[skytexture] = 1;

    texturememory = 0;
    for (i=0 ; i<numtextures ; i++)
    {
    if (!texturepresent[i])
        continue;

    texture = textures[i];

    for (j=0 ; j<texture->patchcount ; j++)
    {
        lump = texture->patches[j].patch;
        texturememory += lumpinfo[lump].size;
        W_CacheLumpNum(lump , PU_CACHE);
    }
    }

    Z_Free(texturepresent);

    // Precache sprites.
    spritepresent = Z_Malloc(numsprites, PU_STATIC, NULL);
    memset (spritepresent,0, numsprites);

    for (th = thinkercap.next ; th != &thinkercap ; th=th->next)
    {
    if (th->function.acp1 == (actionf_p1)P_MobjThinker)
        spritepresent[((mobj_t *)th)->sprite] = 1;
    }

    spritememory = 0;
    for (i=0 ; i<numsprites ; i++)
    {
    if (!spritepresent[i])
        continue;

    for (j=0 ; j<sprites[i].numframes ; j++)
    {
        sf = &sprites[i].spriteframes[j];
        for (k=0 ; k<8 ; k++)
        {
        lump = firstspritelump + sf->lump[k];
        spritememory += lumpinfo[lump].size;
        W_CacheLumpNum(lump , PU_CACHE);
        }
    }
    }

    Z_Free(spritepresent);
}
